EP3SE50F780I3N Altera, EP3SE50F780I3N Datasheet - Page 265

• Manufacturer Part Number: EP3SE50F780I3N
• Description: Stratix III
• Manufacturer: Altera

Altera Corporation
November 2007
I/O Banks Restrictions
Each I/O bank can simultaneously support multiple I/O standards. The
following sections provide guidelines for mixing non-voltage-referenced
and voltage-referenced I/O standards in Stratix III devices.
Non-Voltage-Referenced Standards
Each Stratix III device I/O bank has its own VCCIO pins and supports
only one V
simultaneously support any number of input signals with different I/O
standard assignments, as shown in
For output signals, a single I/O bank supports non-voltage-referenced
output signals that are driving at the same voltage as V
bank can only have one V
for non-voltage-referenced signals. For example, an I/O bank with a
2.5-V V
3-V LVCMOS inputs (not output or bi-directional pins).
Voltage-Referenced Standards
To accommodate voltage-referenced I/O standards, each Stratix III
device’s I/O bank supports multiple VREF pins feeding a common V
bus. The number of available VREF pins increases as device density
increases. If these pins are not used as VREF pins, they cannot be used as
generic I/O pins and should be tied to V
have a single V
time.
An I/O bank featuring single-ended or differential standards can support
voltage-referenced standards as long as all voltage-referenced standards
use the same V
For performance reasons, voltage-referenced input standards use their
own V
voltage-referenced input signals in an I/O bank with a V
below. For example, you can place HSTL-15 input pins in an I/O bank
with a 2.5-V V
Voltage-referenced bi-directional and output signals must be the same as
the I/O bank's V
output pins in an I/O bank with a 2.5-V V
CCPD
CCIO
CCIO
level as the power source. This feature allows you to place
setting can support 2.5-V standard inputs and outputs and
CCIO
CCIO
, either 1.2, 1.5, 1.8, 2.5, 3.0, or 3.3 V. An I/O bank can
REF
CCIO
.
setting.
voltage level and a single V
voltage. For example, you can only place SSTL-2
CCIO
value, it can only drive out that one value
Table
Stratix III Device Handbook, Volume 1
CCIO
7–2.
CCIO
or GND. Each bank can only
Stratix III Device I/O Features
.
REF
voltage level at a given
CCIO
CCIO
. Since an I/O
of 2.5 or
7–47
REF